The Geneva Symmetry Group, Beyond Spacetime, and the Space and Time After Quantum Gravity Project are happy to present

Tim Palmer (University of Oxford):

What physics needs is not a quantum theory of gravity – but rather a gravitational theory of the quantum

Wednesday, 5 April, 18:00

Room L107 at 2, Rue De-Candolle

Anyone who wishes to attend this talk is welcome. In terms of technical difficulty, this talk rates 3/5.

Abstract: Deep theoretical problems raised by the existence of the dark universe and by the conceptually problematic nature of black-hole information are making the need to find a satisfactory synthesis of quantum and gravitational physics more and more pressing. But after more than 50 years of intense research, the holy grail of a satisfactory quantum theory of gravity – quantum gravity for short – does not appear to be in sight. Here I want to propose that the reason for this failure is that we are putting the cart before the horse: instead of trying to fit gravity into the framework of quantum field theory, we should instead be trying to fit the experimental predictions of quantum theory into a more realistic causal geometric framework compatible with general relativity. It may be objected that the various quantum no-go theorems (EPR, GHZ, Bell-CHSH, PBR) make such a proposal impossible. I strongly disagree. I will claim, motivated by the beautiful non-computable fractal geometries of chaos theory, that all these no-go theorems can be resolved in favour of realism and local causality by assuming that the universe can be considered a nonlinear deterministic dynamical system evolving precisely on a type of fractal invariant set in its state space (the word “precisely” being described mathematically by the use of the so-called p-adic metric in state space), and by reinterpreting the complex-number Hilbert vectors of quantum theory accordingly. In describing this “invariant set theory” I will be making essential use of the fact that in the laboratory we cannot screen quantum systems from ubiquitous space-time ripples associated e.g. with distant astrophysical events. This lends weight to the notion, suggested in the title above, that gravity may be playing an essential role in ordinary unitary transformations in laboratory quantum physics (never mind the measurement process) in a way which conventional quantum theory simply cannot account for. For details, see https://arxiv.org/abs/1609.08148.

### Like this:

Like Loading...

*Related*

## About wuthrich

I am a philosopher of physics at the University of Geneva.